The approaches described in this section could be pursued, but are not necessarily approaches that have been previously conceived or pursued. Therefore, unless otherwise indicated herein, the approaches described in this section are not prior art to the claims in this application and are not admitted to be prior art by inclusion in this section.
Certification of an electronic document typically indicates that the document has been preserved to comply with the author's intent. When an author creates a certified document, the author thereby indicates to others that the author approves of the content of the document. In some existing systems, an author may specify the types of changes that are permitted and that allow the document to remain certified.
For example, suppose that a governmental agency creates a form with signature fields. When the form is complete, the agency certifies the document, allowing the users to change only form fields and sign the document. Users can fill in the form and sign the document, but if they remove pages or add comments, the document does not retain its certified status. Certifying a document thus helps to ensure that the document is not altered in a way that does not meet the author's approval.